Such a roof system is disclosed in DE 10 2012 223 709 A1. The known roof system is provided for a vehicle roof of a passenger vehicle. The roof system includes a movable roof part which—as viewed in the longitudinal direction of the vehicle—is connected on each of its opposite longitudinal sides to respective deployment and guide mechanisms which are of identical design and operable in synchronization. Each deployment and guide mechanism has a front deployment lever and a rear deployment lever which are articulated to the roof part. By means of the two deployment and guide mechanisms in opposite roof-sided guide track arrangements the roof part is capable of being transferred from a closed position, in which a roof opening is closed towards the vehicle interior, to a ventilation position, in which the roof part is deployed obliquely rearwards and upwards. From the ventilation position the roof part can be transferred along the longitudinal direction of the vehicle rearwards to an open final position, in which the roof opening is at least largely completely exposed. During the procedure, the movable roof part is shifted rearwards over a stationary roof part of the roof system. The rear deployment lever is coupled to a control lever, whereas the front deployment lever is connected to a guide carriage separate from the control carriage. The guide carriage and the control carriage are displaceable in different guide planes within the guide track arrangement. The guide carriage and the control carriage are capable of being coupled temporarily to each other via a control lever, which lever is capable of being blocked within a stationary latching recess of the guide track arrangement in response to the position of the guide carriage. Said blocking of the guide carriage is necessary in order to transfer the roof part from the closed position thereof to a ventilation position, wherein the control carriage deploys the rear deployment lever upwards, whereas the front deployment lever is retained in a stationary position relative to the longitudinal direction of the guide track arrangement by the control carriage.